Known sports shoes of this kind are described in U.S. Pat. Nos. 3,516,180 and 4,282,659, FR 2 506 ,135, EP 74 513, and patent applications Nos. FR 2 649 594 and EP 623 294.
In these shoes, the support plates are primarily designed to distribute the forces being exerted, at the point of attachment of these plates, between the portion of the foot-insertion perimeter involved and the area opposite the lower leg of the wearer. In accordance with the various construction embodiments disclosed, these plates also make it possible to improve adjustment of the boot upper to fit the morphology of the wearer's lower leg; to reinforce the upper at discrete points, in order, for example to direct certain forces in a preferred direction; or to increase or decrease the upward extent of the support they give to the lower leg, for example in order to increase the wearer's perception of the stresses generated and, in this way, to provide the wearer with the means to react more quickly and with greater precision to certain stresses.
More precisely, with respect to the boots in U.S. Pat. Nos. 3,516,180 and 4,282,659, the support plates are independent of the boot upper, and, accordingly, the position thereof is easily adjustable on the wearer's lower leg. However, because of this autonomous arrangement, they contribute little to reinforcement of the upper and, above all, they must be adjusted to the support position selected by the wearer each time the boot is put on. Moreover, these support plates, which incorporate a one-piece undifferentiated structure and which can be mounted in only one direction, do not allow the level of support they supply to be modified as regards flexibility and stiffness in particular.
In the shoes according to FR 2 649 594, FR 2 506 135 and EP 74 513, the support plates are, in contradistinction to the shoes mentioned above, fastened adjustably in place on the upper. In this way, the wearer may pre-adjust as desired the relative position of the plate on the upper, and, therefore, the position of the support it imparts to the lower leg. On the other hand, moving the position of the plate on the upper either up or down or transversely merely adjusts the position of the support and/or reinforcement given to the upper. It does not, in fact, allow for changes in the level of flexibility and/or stiffness support it imparts to the facing area of the lower leg. More especially with regard to EP 74 513, the support plate is made flexible, but this flexibility remains constant and may not be modified or eliminated.
This problem is solved in the shoe disclosed in EP 623 294, in which, in a specific embodiment, the support plate incorporates two areas of differing flexibilities which can be utilized simply by rotating the plate 180.degree.; however, there is no opportunity to modify the relative position of this plate in relation to the upper.
This boot incorporates a shell surmounted by an upper which, on its inner face and over a portion of its foot-insertion perimeter, incorporates a support plate comprising two areas of differing flexibilities. Using means which fasten it to the upper. this support plate is adjustable angularly between two opposite position, i.e., between 180.degree., each of which corresponds to the activation of one of its flexible areas. Overall, the support plate is four-sided, and the differentiated areas of flexibility are obtained by making weakening notches in one its sides. In this boot, in contradistinction to the boots previously mentioned, it is possible to modify the flexibility and/or stiffness of the support provided by the plate, by positioning one or the other of these areas so that it extends beyond the foot-insertion perimeter of the upper at the point of attachment thereof.
On the other hand, because the support plate is mounted in a rotating arrangement, and, more precisely, because it turns on the pivot-like fastening means which are fixed on the same spot on the upper, upward and lateral adjustment of the plate cannot be effected as chosen by the wearer. Furthermore, since the attachment means form a plate-rotating assembly, the plate is not held constantly and reliably in the chosen angular position. In fact, no element blocks its rotational motion, and it remains free to pivot on itself.